1. Field of the Invention
This invention relates to adjustable ceilings and more particularly, to a retractable ceiling assembly for a poultry house, characterized by a ceiling which can be selectively raised from a flat to a pitched configuration in the poultry house in order to accommodate high-profile equipment or materials therein for cleaning, maintenance or storage purposes. In a preferred embodiment the retractable ceiling assembly includes a pair of ceiling units separated by a ceiling gap in the center of the poultry house, which ceiling gap accommodates the conventional field system equipment used for importing poultry feed into the poultry house. Each ceiling unit is characterized by multiple, elongated rafter units which span the width of the poultry house in parallel, spaced-apart relationship with respect to each other, beneath the respective trusses of the pitched poultry house roof. Each of the rafter units includes a pair of cross members which are pivotally attached to each other at substantially the middle of the rafter unit. A flexible ceiling typically constructed of multiple elongated, overlapping sheets of durable fabric material is mounted on the bottom surfaces of the rafter units. A lift cable is looped around each rafter unit at the middle thereof and is trained around a corresponding pulley which is suspended from the roof of the poultry house, above the rafter unit. A typically manually-operated winch is supported on the interior of the poultry house roof at substantially the center of each ceiling unit, and first and second main cables are connected to a double cable spool of the winch and extend in opposite directions from the winch, above the rafter units. The lift cables attached to the rafter units on one side of the winch are connected to the first main cable, and the lift cables attached to the rafter units on the other side of the winch are connected to the second main cable. Operation of the winch simultaneously winds the first and second main cables on the double cable spool, which draws the lift cables on each side of the winch in concert on the respective pulleys, and the lift cables pivot the initially horizontal cross members of the respective rafter units upwardly with respect to each other. This action bends the ceiling at the pivoting centers of the rafter units and substantially conforms the initially flat ceiling to the pitched configuration of the rafter units. The resulting pitched configuration of the ceiling accommodates high profile equipment or materials in the poultry house when the poultry house is being cleaned, maintained or used for storage purposes. Reverse operation of the winch releases the first and second main cables and attached lift cables, thus causing the cross-members of the rafter units to pivot downwardly in concert with respect to each other by gravity to the horizontal position and lowering the ceiling to the original, flat position, as desired. During the lifting and lowering operations of the winch, the tension exerted on the first main cable by the combined weight of the rafter units on the corresponding side of the winch substantially counterbalances the tension exerted on the second main cable by the combined weight of the rafter units on that side of the winch, and this expedient decreases the weight load on the winch-supporting elements of the poultry house roof. In another embodiment the retractable ceiling assembly is characterized by a continuous ceiling unit, and a ceiling gap is provided between one end of the ceiling unit and the end of the poultry house for accommodating the field system equipment of the poultry house.
Poultry houses are typically constructed with a pitched roof, and insulation paneling is provided on the sloped ceiling inside the poultry house to trap heated air therein during cold weather, or cool air during hot weather. The pitched ceiling accommodates high-profile equipment such as forklifts in the poultry house, such as when cleaning of the poultry house is necessary. However, the pitched ceiling also contributes a substantial quantity of excess space which must be heated or cooled. Accordingly, a more efficient design includes providing a ceiling in the poultry house beneath the pitched roof in order to substantially close the lower portion of the poultry house interior from the upper portion of the poultry house interior which is defined by the pitched roof. This design, however, hinders movement of high profile equipment such as forklifts in the poultry house due to the low position of the ceiling. Accordingly, the retractable ceiling assembly of this invention provides a flat ceiling which substantially closes or seals the upper pitched area of the poultry house from the lower area of the poultry house in order to minimize the area of the poultry house interior which must be heated in cold weather or cooled in hot weather, and also provides a mechanism for raising the ceiling to accommodate high-profile equipment or materials in the poultry house, as needed.
2. Description of the Prior Art
Various types of adjustable ceilings and roofs for buildings are known in the art. A "Multilevel House Trailer" is disclosed in U.S. Pat. No. 3,612,589, dated Oct. 12, 1971, to Harry W. Locher, Jr. The multilevel house trailer is suitable for movement along public roads or highways, and the upper level of the house trailer can be selectively retracted into the lower level. U.S. Pat. No. 4,598,506, dated Jul. 8, 1986, to Arthur H. Nohb, et al., describes a "Swimming Pool Cover" which is designed to cover an indoor, in-ground pool. When in the lowered position, the cover is seated in the swimming pool opening and defines a support floor which is flush with the surrounding floor, and can be raised to become a false ceiling when use of the pool is desired. The cover is raised and lowered on vertical guides fitted with safety ratchets which prevent the cover from inadvertently lowering. A hoist mechanism for the cover is stored in a crawl space or attic above the normal ceiling, and operates by means of cables and pulleys attached to the cover. A "Solar House with Roof Board of Adjustable Inclination" is detailed in U.S. Pat. No. 4,928,444, dated May 29, 1990, to Mitsukazu Horie, et al. The solar house is characterized by a roof structure having pitched roof surfaces, one being downwardly inclined from a top ridge in a southernly direction, and the other being downwardly inclined from the ridge in a northernly direction. South and north side openings extend upwardly through the roof surfaces on opposite sides of the ridge. A shaft is rotatably mounted along the ridge and a roof board, mounted on the shaft, can be pivoted on the shaft between a first position wherein the roof board closes the south side opening and a second position wherein the roof board closes the north side opening. U.S. Pat. No. 5,655,335, dated Aug. 12, 1997, to Arthur Anthony Vermeer, details "Greenhouse Structures and Roof Structures Therefor" including at least two rectangular roof panels each having a lower edge hinged to the structure for movement between a closed, peaked configuration and an open, vertical configuration. Trusses extend transversely between the outer side walls, support members are carried by the trusses, and arch members are each connected at the ends thereof to respective support members for reinforcement of the peaked roof panels against wind. A ridge post member for each arch member extends vertically from its transverse center point and a ridge member is mounted on the ridge post members. The roof panels are pivotally mounted on the arch members, closely adjacent to the support members. A "Storage Building With Ram Openable Roof" is described in U.S. Pat. No. 5,778,604, dated Jul. 14, 1998, to Guy B. Snow. The storage building is characterized by a storage shed which is accessed through a front door or ramp when the roof portions are in an open, supported position. The wall and roof portions of the storage shed are constructed of metal frame members which are covered over with a plywood or vinyl siding. The roof covering can be corrugated galvanized sheeting or wood optionally covered by shingles or transparent or translucent plastic. The roof can be opened and closed by operation of a series of water-operated or electrically-operated rams. U.S. Pat. No. 5,875,591, dated Mar. 2, 1999, to Michael D. Jines, describes "Portable Panels for a Stage Shell". Adjacent backdrop panels and a suspended canopy form the stage shell, wherein the backdrop panels include angular alignment devices for readily and accurately aligning adjacent panels to present a pleasing, uniform appearance, as well as tilt aligning devices for readily aligning the angle of tilt of the backdrop panels. The suspended canopy, formed of individual canopy panels, includes rotatable hinge devices for storing the canopy panels in a substantially vertical position. A stay assembly is provided on the canopy panels for accurately fixing the relative angle of the canopy panels when they are deployed in a performance position above the backdrop panels.
An object of this invention is to provide a retractable ceiling assembly characterized by a ceiling which can be selectively raised and lowered in a building or other structure.
Another object of this invention is to provide a retractable ceiling assembly for a poultry house, characterized by a height-adjustable ceiling which can be selectively raised and lowered in the poultry house in order to accommodate high-profile equipment or materials therein for cleaning, maintenance or storage purposes.
Still another object of this invention is to provide a typically winch-operated, retractable ceiling assembly for poultry houses, which retractable ceiling assembly is characterized by at least one ceiling unit including a height-adjustable, flexible ceiling suspended from the pitched roof of the poultry house and a winch connected to the ceiling by means of cables, wherein operation of the winch causes the initially flat, substantially horizontal ceiling to assume a pitched configuration as the central portion of the ceiling is raised with respect to the stationary edges of the ceiling, and reverse operation of the winch causes the ceiling to resume the initial flat, substantially horizontal configuration.
Another object of this invention is to provide a retractable ceiling assembly for a poultry house, which retractable ceiling assembly includes a pair of ceiling units separated by a ceiling gap in the center of the poultry house and which ceiling gap accommodates the conventional field system equipment used for importing poultry feed into the poultry house.
Yet another object of this invention is to provide a retractable ceiling assembly for a poultry house, characterized by a continuous ceiling unit and wherein a ceiling gap is provided between one end of the ceiling unit and the end of the poultry house for accommodating the conventional field system equipment of the poultry house.
A still further object of this invention is to provide a retractable ceiling assembly for a poultry house, characterized by at least one ceiling unit including multiple, elongated rafter units which span the width of the poultry house, beneath the respective trusses of the pitched roof thereof in substantially parallel, spaced-apart relationship with respect to each other, each of which rafter units includes a pair of cross members pivotally attached to each other at substantially the middle of the rafter unit; a flexible ceiling typically constructed of multiple overlapping, elongated sheets of durable fabric material which ceiling is mounted on the bottom surfaces of the rafter units with the center portion of the ceiling underlying the pivoting midpoints of the rafter units; a lift cable looped around each rafter unit at the middle thereof and trained around a corresponding pulley which is suspended from the roof of the poultry house, above the rafter unit; a winch supported on the interior of the poultry house roof at substantially the longitudinal midpoint of the ceiling unit; and a first main cable which is connected to the winch and to the lift cables on one side of the winch and a second main cable which is connected to the winch and to the lift cables on the other side of the winch, wherein operation of the winch simultaneously winds the first and second main cables on the winch, the lift cables on the respective sides of the winch are drawn in concert on the respective pulleys and the lift cables pivot the cross members of the respective rafter units upwardly with respect to each other, such that the attached ceiling substantially conforms to the pitched configuration of the rafter units. The resulting pitched configuration of the ceiling accommodates high profile equipment or materials in the poultry house when the poultry house is being cleaned, maintained or used for storage purposes. Reverse operation of the winch releases the first and second main cables and the respective sets of attached lift cables, thus causing the cross members of the rafter units to pivot downwardly by gravity and lowering the ceiling to the original, flat position, as desired. During the lifting and lowering operations of the winch, the tension exerted on the first main cable by the combined weight of the rafter units on the corresponding side of the winch substantially counterbalances the tension exerted on the second main cable by the combined weight of the rafter units on the other side of the winch, and this decreases the weight load on the winch-supporting elements of the poultry house roof.